Apparatus for compressing air or other gas.



F. W. S. STOKES. APPARATUS FOR COMPRESSING AIR OR OTHER GAS.

APPLICATION HLED JULY 2 1914. 1,175,484, v Patented Mar. 14,1916.

' 2 SHEETS' SHEET 1.

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APPARATUS FOR COMPRESSING AIR OR OTHER GAS.

APPLICATION FILED JULY 2.19M.

Patehted Man 14, 1916.

2 SHEETS'SHEET 2.

"Unit FREDERICK WILFRID SCOTT STOKES, OF LONDON, ENGLAND.

APPARATUS FOR COMPRESSING AIR OR OTHER GAS.

Specification of Letters Patent.

Patented Mar. it, 1916.

Application filed July 2, 1914. Serial No. 848,642.

To aZZ whom it may concern:

Be it known that I, FREDERICK VVILFRID Soorr Sronrs, subject of the King of England, residing at London, in England, have invented certain new and useful improve ments in Apparatus for Compressing Air or other Gas, of which the following is a specification.

This invention relates to apparatus for compressing air or other gas and has particular reference to compressors in which gas at two different pressures is drawn or allowed to pass into the cylinder before the compression stroke, as for instance when working on what is known as the multiple effect compression system. In such apparatus it is necessary to provide valves to control the passage to the cylinder of the low pressure and high pressure gases and various forms of mechanically operated valves have been suggested.

The primary object of the present invention is the construction of a simple and efiicient valve to control the high pressure gas so that it is not allowed to pass into the cylinder until the desired moment which is generally at or near the end of the low pressure suction stroke.

Another object of the invention is the construction of thevalve so that existing compressor cylinders may be converted readily, to work with multiple effect compression.

According to this invention the valve for the high pressure gas is kept closed during the required period by magnetic action an electromagnet or solenoid being so disposed relatively to the valve that after the valve is closed it is kept closed until the winding of the electrcmagnet or solenoid is dec'nergizcd by the breaking of its circuit, the valve is then allowed to open or be moved away from its seat by the higher pressure gas.

In ccniunction with the magnetically controlled high pressure valve some convenient form of low pressure suction valve is employed, one arrangement being for the two valves to be placed one above the other the high pressure valve closing say the downward path of the high pressure gas and the low pressure valve closing the upward path of the low pressure gas. The two valves may be quite close together and when either of them is open the gas may flow into a chamber between them and then away through a transverse passage to the com- Prssser. art san... .Qeavsaieatlr the- :two

valves are so made that they are inclosed ina cylindrical casing which forms a plug capable of being placed and secured within the bore or recess usually provided for the valve in the block of an ordinary compressor.

In the accompanying drawings, Figures 1, 2, 3, 4 and 5 are central vertical sections through various constructions of magnetically controlled valves all according to this invention.

Like letters indicate the drawings.

vVith reference first to Fig. 1 A is the cylinder and B the suction passage of a compressor the suction passage communicating in any usual way with The conduit from the suction passage to the cylinder is controlled by a valve 0 normally kept down upon its seating by a spring D. This valve is contained in a chamber E formed in a plug-like casing F, the chamber E opening through ports E into an annular like parts throughout space G in communication with the cylinder A. Above the spring D and forming the upper bearing surface for it is a block H screwed into the casing F and having a central recess H to accommodate the stem of a valve J. The surface. J. of this valve is formed so that when in the position shown in Fig. 1 it closes the lower end of a passage K which is in communication with some source of gas at higher pressure such as a multiple efiect receiver. The upper portion of the valve J is flanged as at J and is supported by a spring L and the flanged portion of the valve serves as an armature or keeper for an annular electromagnet formed by portions of the material forming the plug-like casing F and excited by a winding M which is contained in a recess formed for it. The ends of the winding are brought out in any convenient wa and are connected to some suitable form of contact-making apparatus and to a battery or other source of electrical power, but these details are not shown as in themselves they do not form part of the present invention. After the winding M hasbeen placed in the recess formed for it the recess is plugged as at M preferably by gunmetal or some other nonmagnetic material to prevent the access of the gas to the winding. A lining or bushing M of non-magnetic material is placed between the valve J and the adjacent surface of the inner portion of the casing F to Prevent. states a re stick es a source of low pressure gas.-

through residual magnetism. Holes or passages J are formed in the valve so that when it is opened gas may pass out readily fro-m the passage K and'mayincidentally clear the surface J of the valve frcm any dirt or grit. The stem of the valve J that is, the portion accommodated in the recess H is provided with small pistonrings J* and has a passage J 5 formed in it. At the bottom of the block H a small aperture is provided connecting the recess H with the undersurface of the block and this aperture is fitted with a simple non-return valve N.

' The action of the valve illustrated in Fig. 1 is as follows: Supposing the valve J to be in the position shown the passage K for the high pressure gas is closed and the valve J of high pressure gas.

is kept up against its seating by the electromagnet the winding M of which is energized. If now the suction stroke of the compressor piston commences, the valve C is lifted from its seating against the action of the spring D and low pressure gas enters the cylinder from' the suction passage B. At the end of the suction stroke the valve C is closed by the action of its spring D and the circuit containing the winding M is broken. The high pressure gas then forces the valve J down against the action of its spring L and high pressure gas flows from the passage K past the valve J down through holes H in the block H into the chamber E and thence through the passages E into the cylinder,v thus bringing up the pressure of the charge of gas in the cylinder to that of the multiple effect receiver or other source This action is momentary and as soon as the valve J is equalized the valve isreturned to its seating by its spring L and is held there by the electromagnet owing to the fact that the winding'M has now been energized again. The compression stroke now commences and the gas from the cylinder is forced out through the usual outlet valve which is not shown. The stem of the valve J fitting with its rings J in the recess H acts as a dashpot to prevent anvjar consequent on the opening of the valve. At the commencement of its downward motion the valve J can more quite freely but very soon i the upper end' of the opening J in the stem is closed and consequently the gas in the bottom of the recess H cannot escape as the val e N is anon-return valve and a cushion isthus provided for the stem. Supposing the valve J has not'been returned to its seating before the commencement of the compression stroke, the compression pressure will open thevalve N inward and tend to close the valve by acting on the lower end of the stem.

The valve illustrated in Fig- 2 does not differ .materially from that described with reference to Fig. 1 except that there is no the pressure around valve in the bottom of the block H and that there is a small passage J extending right through the valve J and terminating at the top with a guarded opening- The valve J is of simpler construction than that shown in Fig. 1 for it has only one face the central portion of which serves to close the passage K forthe high pressure gas, while the outer annulus acts as the armature or keeper for the electromagnet. As in the previous con struction gunmetal linings or facings are provided where desirable as for example at M 1 3 and M. The operation of this ,con-

struction of valve is substantially similar to that already described with reference to Fig. 1 except that the compression pressure does not have access to the lower surface of the valve stem.

FigslB and 4: are examples of constructions of valvesaccording to this invention which are suitable for use in compressors where the inlet valve opens directly into the compressor cylinder, in such cases the nor mal suction valve 0 may be retained and a second low pressure suction valve as well as 'a magnetically controlled valve for the higher pressure gas may be added in the suction valve chamber. In Fig. 8 this second low pressure suction valve is in the form of a faced ring P controlling inlet ports F in the plug-like casing F, these ports communicating with an annular chamber F in connection with the source of low pressure I The stem of the normal'suction valve with a disk 0 acted upon by two springs O and O the top of the spring 0 bearing upon the under side of the second low pressure suction valve P while thebotgas. 0 1s provlded tom end of the spring 0 bears upon the top of a valve J which is magnetically controlled by an electromagnet with a winding M. This valve J controls the conduit K through which the higher pressure gas fr m V the multiple effect receiver passes. The valve is shown in position near the head of the compresser cylinder A. In operation, on the suction stroke. the high pressure valve J is kept closed by its electroma net and the normal suctionvalve Otis opened. Under the suction low, pressure gas enters from the chamber F through the ports u and the second valveP moves away from its seating opening the ports so that the low pressure gas flows intothe cylinder. At or about the end of the suction stroke the electroma net is de'nergized. the valve P closes, the valve Jrises and high pressure gas enters and flows up throu hthe interior of the casing and throu h the normal suction valve 0 into the cylinder. At the commencement of the compression stroke the val e 0 is closed. the valve J is also closed and is retained in its closed position by the ene gizin of the electroma net.

Fig. 4 illustrates a modified construction the valve shown in Fig. 3. Like that valve thestem of the normal suction valve 0 is provided with a disk 0 acted upon by two springs O and 0 But instead of providing a separate second low pressure valve P as in the construction shown in Fig. 3, in Fig. 4 the high pressure valve J 8 is formed with a cylindrical extension J forming a 7 piston valve controlling the low pressure inlet' ports F On the commencement of the suction stroke the valve 0 opens and low pressure gas passes into the cylinder through the ports F Then, on the magnet winding M being deenergized the high pressure valve J is raised against its spring 0 the ports F are closed and high pressure gas passes up around the stem of the valve 0 into the cylinder. At the appropriate moment the spring 0 returns the valve J to its seating where it is retained by the action of the electromagnet whose winding is now again energized. I

Fig. 5 illustrates a valve according to this invention arranged for use in the same manner as the valves described with reference to Figs. 3 and 4;, but in which the normal suction valve 0 is dispensed with. Ihe arrangement is generally similar in construction and operation to the forms illustrated in Figs. 1 and 2 except that the position of the valves is inverted, the low pressure suction valve C being uppermost and the high pressure valve J beneath. On the suction stroke'the valve C moves downward against the action of its spring D and the low pressure gas enters from the annular chamber F through ports F to a chamber F Thence it passes out under the valve and through passages F into the cylinder. During the entrance of the low pressure gas, as in the other constructions previously described, the magnet winding M has been energized and the high pressure valve J kept on its seating. At the end of the compres sion stroke the circuit is broken and high pressure gas passing through the conduit K raises the valve J and passes up through passages H and F into the cylinder the low pressure valve C being closed by its spring.

It will be noticed that the stem of the valve J slides in a recess H in the block H forming a dashpot arrangement and that a spring L is provided to return the high pressure valve J to its seating.

It is to be understood that in all the constructions linings or bushings of non-magnetic material may be provided between adjacent relatively movable parts where no flow of magnetic lines is required in order to prevent sticking.

The various forms illustrated and described are given by way of example and it is to be understood that modifications or alterations of details may be made without departing from the spirit of this invention. For example, the armature or keeper of the electromagnet need not necessarily be a part of the actual high pressure valve but may be connected to the stem of that valve. Or the magnet when energized may grip some member attached'to the valve instead of merely retaining itby magnetic attraction. Again arrangements may be made for the armature to be polarized, that is it may be a permanent magnet of hard steel or may itself have a magnetizing coil. In such a case the releasing of the armature might be insured by reversing the current in the magnet coil, but this arrangement is not generally necessary and it is preferred to use an armature or keeper made of soft iron.

In' some cases the compression pressure may be utilized to retain the high pressure valve in contact with its seating the gas entering during the compression stroke into a chamber beneath the valve stem and being entrapped by a non-return valve somewhat similar to the valve N shown in Fig. 1. In such cases, however, the magnet and its armature would preferably be beneath the block H in which the high pressure valve works and small leak passages would be provided from the face of the electromagnet to the interior of the chamber H, such leak passages being opened when the keeper was released to allow the valve to be blown open by the high pressure gas.

What I claim as my invention and desire to secure by Letters Patent is 1. In apparatus for compressing air or other gas the combination of a compressor cylinder having an inlet through which both high and low pressure gases enter, a low pressure suction valve, a valve for the high pressure gas and electro-magnetic means for keeping such high pressure gas valve closed during the required period.

2. In apparatus for compressing air or other gas the combination of a compressor cylinder,a plug or casing fitting into an opening in the wall of said cylinder, inlets or passages in such casing for high and low pressure gas respectively, a valve controlling each of said passages, an inlet from the casing to the compressor cylinder and electro-magnetic means for keeping the high pressure gas valve closed during the required period.

3. In apparatus for compressing air or other gas the combination of a compressor cylinder having inlets for high and low pressure gas respectively, valves controlling such inlets, electromagnetic means for keeping the high pressure gas valve closed during the required period and a dashpot for cushioning the motion of the valve.

4. In apparatus for compressing air or other gas the combination of a compressor cylinder having inlets for high and low such inlets, electromagnetic means for keeping the high pressure gas valve closed during the required period, a dashpot for cushioning the motion of such valve and springs tending to close both the valves.

5. In apparatus for compressing air or other gas the combination of. a compressor cylinder having inlets for high and low pressure gas respectively, valvescontrolling such inlets, electromagnetic means for keeping thehigh pressure gas valve closed during the required period, a dashpot for cush ioningthe motion of the valve provided with an opening leading to the compressor cylinder and a non-return valve controlling said opening. I

6. In apparatus for compressing air or other gas the combination with acompressor cylinder of a plug-like casing fitting into an opening in said cylinder and having inlets for high and low pressure gas and an opening into the cylinder controlled by a suction valve, of a second suction valve within the casing controlling the inlet for low pressure gas, a valve for controlling the inlet for'high' pressure gas, electromagnetic means for keeping such high pressure gas valve closed during the required period and springs tending to close the second suction valve and the'high pressure gas valve the arrangement being such that when the ordinary suction valve is open the second suction valve first opens to allow low pressure D suction valve is closed and the magnetically controlled valve allowed to open so that high pressuregas may pass into the cylinder.

7. In apparatus for compressing air or cylinder of a plug-like casing fitting into an opening in said cylinder and havinginlets for high and low pressure gas and an opening into the cylinder controlled by a suction valve, of a valve within the casing controlling the inlet for high pressure gas and having an extension which forms a piston valve acting as a second suction valve controlling the inlet for low pressure gas, electromagneticmeans for keeping the high pressure gas valve closed during the required period and springs tending to close the valves substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of.

two subscribing witnesses.

FREDERICK WILFRID SCOTT STOKES.

Witnesses:

RIPLEY WILSON, O. J. WORTH.

Copies of this patent may be obtained for five cents each. by addressing the Commissioner of Patents.

Washington, D. C.

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